Edwin strain



(No Model.)

. B. STRAIN.

ART 0F MAKING. SPLIT NEEDLES. No. 568,418. Patented Sept. 29, 18946. m' D; c Li D In 'L UNrTED STATES EDIVIN STRAIN, OF MELROSE, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO HELEN A. BLANCHARD, OF NEIV YORK, N. Y.

ART oF MAKING sPLlT NEEDLES.

SPECIFICATION forming part of Letters Patent No. 568,418, dated September 29, 1896.

Application filed June 29, 1894. Serial No. 516,065. (No model.)

To all whom it may concern.-

Beit known that I, EDWIN STRAIN, of Melrose, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in the Art of Making Split Needles, of which the following is a specification.

This invention relates to that class of needles in which the body of the needle is longitudinally divided throughout a portion of its length, one of the divisions being a thin and narrow spring separated from the main part of the needle at a distance from the point thereof, so that a thread may be inserted into the slot between the divisions and moved down into the eye of the needle.

Heretofore the narrower division or spring has either been made in a separate piece and soldered or otherwise secured to the main body of the needle, or has been formed by cutting a slot in the body of the needle after the formation of the eye. The first-named construction is objectionable in that it is difficult and expensive, and, further, in that it is difficult to provide a needle with a smooth surface at the point where the spring is united to the body of the needle near the point thereof. The second method above alluded to has has not been successful, because of the difiiculty experienced in cutting a siot in the body of a cylindrical needle and giving the proper proportions to the spring and the main body of the needle, the metal removed in forming the slot necessitating the formation of a very attenuated spring, which is liable to be irregular in thickness and generally undesirable. l

My invention has for its object to enable a desirable and practical needle of this class to be made by cutting a slot in the body of the needle, thus making the spring integral with the needle and avoiding a rough surface at the junction of the spring and needle.

The invention also has for its object to provide an improved construction of a split needie, particularly with respect to the guard which is attached to the shank of the needle and projects over the free end of the spring. To these ends my invention consists in the part of this specification, Figure l represents y a side view of the incipient needle in an early stage of its manufacture. Fig. 2 represents a section on line 2 2 of Fig. 1. Fig. 3 represents a view showing the form produced by the next step in the method of making the needle. Fig. 4 represents a section on line i fi of Fig. 3. Fig. 5 represents a view of the incipient needle shown in Fig. 3, taken from a different point. Fig. 6 represents a section on line 6 6 of Fig. 5. Fig. 7 represents aview similar to Fig. 3, showing a slot cut in the body of the needle. Fig. 8 represents a section on line 8 8 of Fig. 7. Fig. 9 represents a side view showing the needle reduced to a cylindrical form. Fig. lO represents a section on line 10 10 of Fig. 9. Fig. 11 represents a view showing the needle provided with an eye and the upper portion of the spring cut away. Figs. 12 and 14 represent side views showing the completed needle. Fig. 13 represents a section on line 13 13 of Fig. 12. Fig. 13 represents a section on line 13a 13L of Fig. l2. Fig. 15 represents a section on line 15 15 of Fig. 14:. Fig. 16 represents a side view of y the guard before its application to the needle.

The same letters of reference indicate the same parts in all the igures.

In carrying out my invention I iirst form a cylindrical needle-blank, the body portion a of which is of greater diameter than the body portion of the completed needle, the said body portion having therefore an excess of material over that required or desirable in the finished needle. I then compress the body portion a in such manner as to form two flat sides or faces a ct thereon, as shown in Figs. 3, 4, 5, 7, and 8, this operation displacing portions of the metal and making the body oblong in cross-section. This compression takes place while the metal is comparatively soft, or, in other words, while it is soft enough to permit of the body being readilyattened by compression. I then out a lon'- gitudinal slot a2 in the flattened body portion, said slot being nearer one edge than the other,

as shown in Figs. 7 and 8, so that. the portion a3 of the'v body left at one side of the slot is considerably narrower than the portion d'1 left at the other side, the narrower portion constituting the spring above mentioned. After cutting the slot. a2 I subject the needle-body to the action of dies, or by other suitable means reduce the body to a cylindrical form, as shown in Figs. 9 and lO. The removal of metal involved by the formation of the slot a2 causes a considerable reduction of the diameter of the needlebody as compared with t-hat of the blank shownfin Fig. l, the body being thus reduced to the diameter desired for the finished needle. The reduction of the needle-body to cylindrical form brings together the sides of the slot and leaves the needle in substantially the same form as an ordinary solid needle, the only difference being that the needle is longitudinally divided from a point near its penetrating end to a point at or near the base of its shank. rlhe pressure necessary to return the body to cylindrical form and close the sides of the slot partially hai-dens it and places it in better condition for final tempering. I The spring may now be completed by cutting away the upper portion of the narrower division of the needle-body, as shown in Fig. 11, thus forming a i'ree end or tongue a5, which is preferably slightly bent or curved outwardly to facilitate the introduction of the thread into the slot. I prefer to cut out some of the inaterial of the body of the needle at the point where the spring is cut through, thus forming a recess 7)' to facilitate the insertion of the thread. The eye c is formed in the needle at one side of the spring, the eye being so arranged that it opens into the slot between the main body of the needle and the spring.

For sewing-machine use the needle is or may be provided with the usual longitudinal groove c', Figs. ll, l2, and 13, extending from the eye c and below it to the upper portion of the needle-body (l represents a guard, which is a small metal plate, preferably of oval form and eoncavo-convex in cross-section, said guard being provided with an elongated stem CZ. The shank of the needle is provided with a longigitudinal slot e, Figs. 5 and 6, formed to receive and closely t the stem d', so that when said stem is inserted in the slot it may be Securely fastened to the needle by exerting pressure upon the shank in such manner as to crowd the sides of the slot e inward against the stem d. The elongated form of the stem CZ', giving it an extended bearing on the shank of the needle, enables the guard to be very securely attached by the described compression of the slot e. The guard projects below the free end of the spring, as shown in Figs. l2, 14:, and l5, and is arranged so that the thread can be readily slipped between it and the free end of the spring in an upward direction, the thread then entering the recess Z1', from which it can be readily moved downwardly through the slot into the eye c.

It will be seen that by making the needleblank larger than the size required for the finished needleI am enabled to readily form a longitudinal slot in the needle-body in such manner as to make a practical and etfective spring of uniform width without the difliculty that would attend the operation of slotting the body if the latter were reduced to the diameter required for the completed needle before the slotting operation. It will also be seen that by iiattening the blank to give it oblong form in crosssection before cutting the slot I greatly facilitate the slotting opera-tion, first, because the rotary saws which I use in cutting the slot can much more readily enter flat'surfaces than cylindrical ones, and, secondly, because said saws do not encounter as much metal in cutting through from one flat side to the other as they would in cutting through a cylindrical body. The reduction of the needle to a cylindrical form, as stated, gives the needle practically the same forni as that of an ordinary needle which is not slotted, so that the point of the needle is as perfect and is adapted to penetrate as readily as that of an ordinary needle.

I do not limit myself to the described improvements in connection with a sewing-machine needle, although that is the only form of needle which I have here shown and described. l desire, however, to apply myimprovenient to any needle to which it is adapted to be applied.

In order to make a smooth cut, I run the needle between two saws arranged in the same plane and having their teeth intermeshing like the teeth of a gear. It is evident that this will make a perfectly smooth cut, and it is also evident that if the teeth of the saws do not so intermesh a bur will be left on the sides of the needle forming the slot.

I claim- The method of making split needles, which consists in irst making a cylindrical needlebody with an excess of metal diametrically, then, and while the metal is in a comparatively soft state, partially flattening the body, then cutting a longitudinal slot therein and thereby removing the surplus metal, and then compressing the body to partially harden it preparatory to inishing, said compression giving the body the desired cylindrical diameter and at the same time closing together the sides of the slot.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 20th day ot June, A. D. ISM.

IJDVIN STRAIN.

Titnesses z HELEN A. BLANCHARD, C. F. BROWN.

ICO

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